George Lucas approached Mark Hamill and Carrie Fisher before he sold Lucasfilm. He sat them down almost a year before and talked to them about a new Star Wars trilogy; if my sources are correct Disney basically inherited the deals he made with them. Lucas had a plan for the new trilogy, had an outline, and over the last couple of years fandom has speculated about how much of that outline actually made its way through the sale and then through JJ Abrams' development process. How much of George Lucas' vision made it into The Force Awakens?
Depends on who you ask.
Talking to Vanity Fair Lucasfilm honcho Kathleen Kennedy said:
“We’ve made some departures” from Lucas’s ideas, Kennedy conceded, but only in “exactly the way you would in any development process.”
That sort of doesn't line up with what is said elsewhere in the same article, which lays out the process that Lawrence Kasdan and JJ Abrams took once they got Michael Arndt off the project:
As of early November 2013, the studio walls and whiteboards were filled with ideas, but the actual narrative hadn't been set in place. Abrams and the Empire Strikes Back/Return of the Jedi co-writer Lawrence Kasdan took over, starting from something very close to scratch. “We didn’t have anything,” Kasdan told Handy. “There were a thousand people waiting for answers on things, and you couldn’t tell them anything except, ‘Yeah, that guy’s in it.’ That was about it. That was really all we knew.” The two men then hashed out the story in conversations as they walked around Santa Monica, New York City, London, and Paris, and kept refining the script even as production began.
The Vanity Fair story seems to throw Arndt under the bus a bit, saying he never managed to finish his script (presumably based more on Lucas' ideas). That feels unfair to me, and my sources have indicated that Arndt got shut out of the process as opposed to 'failing to pull a script together.'
What was Lucas' version like? It's not clear, but the article intimates that it focused on teens, and that Disney was worried that more teens would make the new films feel like a return to the Prequel Trilogy. They wanted to get back to the tone of the Original Trilogy, and so they aged up the characters. It does seem as if everything was thrown out, although some elements remained - this is a generational story, after all, and so some of the characters in both Lucas' and Abrams' versions are related to the original trilogy characters.
The final answer to the question in the headline: Star Wars: The Force Awakens probably bears little to no resemblance to what George Lucas had planned. We're entering a whole new phase of Star Wars, one with the most minimal Lucas participation possible. Whether that's good or not is up to your view on Lucas' last few decades of work. For me? This is part of why I am so excited about the future of Star Wars.